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Asp.NET server control events not firing

Thanks for all who reads. I have a code issue that has been discussed many times on stackoverflow, but I can't make the provided solutions work.
It's about server control that contain other controls and I can't fire their events.
My issue is simple, i need to add any numbers ok LinButton into my server control. this is my code:
protected override void CreateChildControls()
{
for (int i = 0; i < IndiceValue; i++)
{
LinkButton imageTemp = new LinkButton() { CommandName = String.Format("{1}_{0}", CommandNames, i), Text = i.ToString(), ID = Guid.NewGuid().ToString()};
imageTemp.Click += ImageTempOnClick;
this.Controls.Add(imageTemp);
}
base.CreateChildControls();
}
I have a custom event in my control:
public delegate void IndiceFiabiliteCommand(object sender, IndiceFiabiliteCommandEventArg e);
public event IndiceFiabiliteCommand Command;
And theorically, when any of the LinkButton is clicked, I want the user to be warn that any of the LinkButton has been clicked. I give him all the needed infos but i don't think this part is the problem.
Last thing to know is that I implement INamingContainer and I tried to implement both, IPostBackDataHandler and IPostBackEventHandler but it didn't worked.
I hope it's understandable enough
thanks!

The problem is ID = Guid.NewGuid().ToString()
You cannot have dynamically created control with dynamic id. Change the code to
... i.ToString(), ID = i.ToString()
Basically, dynamic control's ID must be same as the ID originally created.
Otherwise, new control is created on every post-back, and it cannot find the control which causes the post-back.
FYI: if you need to catch an event, I would like to suggest to use CompositeControl which already have INamingContainer.
Note: it is just what I found based on your code; it might be other issue too.

Access parent DIV of user-control (ascx) from its code behind

From within the code-behind of an ASP .NET web user-control (ascx) I need to get access (at runtime) to its parent, a div element. The aim is simple as to modify the visibility of the mentioned parent div.
I can not touch so much of the web-page code so I'd need a solution requiring only modifications in the user-control's code behind.
So in the HTML "part" of the code of the web page I have this:
<div id="parentDIV" runat="server">
<uc:MyUserControl ID="myUserControlInstance" runat="server" />
</div>
I'd like to do in the code behind of the user-control something like this:
this.Container.Visible = false;
Note that I'm not asking if it is a good practise or not to do this.
EDIT:
The user-control code behind does not "know" about the ID of the parent DIV.

I would hide it on the client. Decorate your user control container (div?) with a class like "awesomeUserControl". Then emit some javascript using the ScriptManager object to hide the parent like this:
ScriptManager.RegisterStartupScript(this, this.GetType(), "HideMyAwesomeUserControl", "$('.awesomeUserControl').parent().hide();", true);

The better way...
What you should do is to create a custom event in your user control, to which your container will subscribe - very much like subscribing to a button event, only this is your custom control. This event passes information to your container which can then discern from it what it needs, such as whether or not the div should/not be visible.
It might look something like:
protected void Page_Load(object sender, EventArgs e)
{
this.myuserControl.Update += new MyUserControlUpdateEventHandler(myuserControl_Update);
}
void myuserControl_Update(object sender, MyuserControlEventArgs e)
{
this.parentDiv.visible = !e.ShouldHideUI;
}
This method will decouple your parent with the user control, i.e. your user control doesn't have to have any knowledge at all of the parent's controls, nor should it.
If you are curious, here is a rough example of how your user control will define such an event:
public class MyuserControlEventArgs : EventArgs
{
public bool ShouldHideUI { get;set;}
public MyuserControlEventArgs (bool shouldHideUI)
{
this.ShouldHideUI = shouldHideUI;
}
}
public delegate void MyUserControlUpdateEventHandler(object sender, MyuserControlEventArgs e);
public event MyUserControlUpdateEventHandler Update;
protected void OnUpdate(MyuserControlEventArgs e)
{
if (Update!= null)
Update(this, e);
}
Your user control will simply need to call OnUpdate whenever it feels its subscribers need to know about it.
The Quick and Dirty way...
If you need quick and dirty, then try this (inside your user control):
TheParentControl parentControl = (TheParentControl)this.Parent;
parentControl.ParentDiv.Visible = true;
The key is to cast to the appropriate type (apparently your user control would know what type of parent it has), then set the parent's property. You might expose your div as a property in the parent control. Note, that parent could be ANY control (page, FooControl, BarControl, whatever) whose control collection your user control resides. Once you get a handle to the parent, you can even FindControl() to find a control by name.

You're almost there....
this.Parent.Visible = false;

When all controls get rendered, the HTML Parent child controls can be determined like below.
I am using while loop, so in case you add some other intermediate control, it may not give crash or unexpected results.
public Control ParentControl
{
get
{
Control ctl = this.Parent;
while (true)
{
if (ctl == null) break;
if (ctl.ID.Equals("parentDIV"))
{
break;
}
ctl = ctl.Parent;
}
return ctl;
}
}
if(ParentControl != null)
ParentControl.Visible = true|false;

Am I missing something, it sounds like you have a usercontrol and an aspx page (both have code behind's).
The user control appears to have been added to the aspx page, wrapped in a div. YOu've made the div control runat server (though you can still do this via htmlcontrol).
All you ned to do to manage the div is:
parentDIV.visible = false;
or whatever you need to do with the div.
Why does the UC code behind need to know about the APSX pages DIV, it doesn't.

Dynamically change MasterPage and ContentPlaceHolderID of asp content tag?

I have a page which initially inherited from MastePage.master . And I want to use the same page but with different masterpage(MasterPage2.master) at some other place in my project. For that I am using the following code.
private void Page_PreInit(object sender, EventArgs e)
{
if (Request.QueryString["Update"].ToString() == "New")
{
this.MasterPageFile = "MasterPage2.master";
Content con = new Content();
con = (Content)this.FindControl("Content1");
this.Content1.ContentPlaceHolderID = "ContentPlaceHolder2";
}
}
I am also trying to set the asp content tag's ContentPlaceHolderID to ContentPlaceHolder2 which is from MasterPage2.master. Initially it was ContentPlaceHolder1.
But I am getting null value at con = (Content)this.FindControl("Content1");
Thanks

Page internally stores in private '_contentTemplateCollection' hashtable. it uses ContentPlaceHolderID property as key and stores special class (that will be used to build/initialize Content tag) as a value
- so to change ContentPlaceHolderID value (defined within markup) you need to modify this hashtable, remove old entry linked with old Id and add other entry with new Id
- you need to change ContentPlaceHolderId before creating master page otherwise an exception will be thrown in runtime
- best place to change Ids is Page 'preinit' event and if it is better to change Ids before change master page (if you will change master page at runtime)
To change ContentPlaceHolderID of Content tag, you can use following function in Page PreInit event
public static void AssignContentToNewPlaceHoldersWithinPage(Page pPage, string pOldId, string pNewId)
{
if (pPage == null || string.IsNullOrEmpty(pOldId) || string.IsNullOrEmpty(pNewId))
{
return;
}
// Try to get a reference to private hashtable using fasterflect free reflection library in codeplex (http://fasterflect.codeplex.com/)
// you can replace following line with standard reflection APIs
var lTmpObj = pPage.TryGetFieldValue("_contentTemplateCollection");
if (lTmpObj != null && lTmpObj is Hashtable)
{
var _contentTemplateCollection = lTmpObj as Hashtable;
if (_contentTemplateCollection.ContainsKey(pOldId) && !_contentTemplateCollection.ContainsKey(pNewId))
{
var lTemplate = _contentTemplateCollection[pOldId];
_contentTemplateCollection.Add(pNewId, lTemplate);
_contentTemplateCollection.Remove(pOldId);
}
}
}
function parameter are
pPage is reference to page instance contains content tag
pOldId is ContentPlaceHolderId property value in markup - the Id you want to change
pNewId is the new Id you want to use
I hope that my answer will be useful and I am sorry if my English language is not good

You can dynamically change the Master Page at runtime, but you need to use the same ContentPlaceHolder IDs. That way, your pages will work with either Master Page without adding extra code to change the IDs at runtime.
private void Page_PreInit(object sender, EventArgs e)
{
if (Request.QueryString["Update"].ToString() == "New")
{
this.MasterPageFile = "MasterPage2.master";
}
}
You can even test that your page will work with either Master Page in the Visual Studio design/markup view by changing the MasterPageFile in the <% Page %> directive in the .aspx markup.

The Master Page can be changed by overriding OnPreInit.
protected override void OnPreInit(EventArgs e)
{
base.OnPreInit(e);
MasterPageFile = "~/MasterPages/MyOther.Master";
}
But for the ContentPlaceHolders I would suggest to create new ContentPlaceHolders with the same name in both of your MasterPages.

How call GetWebResourceUrl() when Page is null ?

I built custom ASP.NET control and it's working fine when I add it manually (drag and drop) or by code to controls in markup.
The custom control, MsgBox, had resources like JavaScript, CSS and images embedded in and the problem appeared when I tried to Render the control in class to return its HTML code, the Page instance is null and the "GetWebResourceUrl" needs it:
Page.ClientScript.GetWebResourceUrl(.....)
is there any way to get the resourceurl ? Here is my render code:
protected override void RenderContents(HtmlTextWriter writer)
{
using (PlaceHolder plh = new PlaceHolder())
{
if (Page != null)
{
if (DesignMode || Page.Header == null)
RegisterCSSInclude(plh);
}
HtmlGenericControl container = new HtmlGenericControl("div");
container.EnableViewState = false;
container.InnerHtml = "Control html code";
plh.Controls.Add(container);
plh.RenderControl(writer);
}
}
RegisterCSSInclude is method to register my css files:
private void RegisterCSSInclude(Control target)
{
// CSS
bool linkIncluded = false;
foreach (Control c in target.Controls)
{
if (c.ID == "MsgBxStyle")
{
linkIncluded = true;
}
}
if (!linkIncluded)
{
HtmlGenericControl globalCsslink = new HtmlGenericControl("link");
globalCsslink.ID = "MsgBxGStyle";
globalCsslink.Attributes.Add("href", Page.ClientScript.GetWebResourceUrl(typeof(MessageBoxCtrl), "MessageBox.MsgBxStyles.WeDevMsgBox.css"));
globalCsslink.Attributes.Add("type", "text/css");
globalCsslink.Attributes.Add("rel", "stylesheet");
globalCsslink.EnableViewState = false;
target.Controls.Add(globalCsslink);
HtmlGenericControl csslink = new HtmlGenericControl("link");
csslink.ID = "MsgBxStyle";
csslink.Attributes.Add("href", Page.ClientScript.GetWebResourceUrl(typeof(MessageBoxCtrl), "MessageBox.MsgBxStyles." + Style.ToString().ToLower() + ".css"));
csslink.Attributes.Add("type", "text/css");
csslink.Attributes.Add("rel", "stylesheet");
csslink.EnableViewState = false;
target.Controls.Add(csslink);
}
}
Update:
PS: I'm tring to use control in generic handler (ashx) where I call ShowMsgBox method which is a method in a class and not in a page or user control.
ShowMsgBox method should create an instance of MsgBox control and render it then return the html code to ashx class :
var htmlCode = MyClass.ShowMsgBox("myMsg");
context.Response.write(htmlCode);

I built a custom ASP.NET control ...
I'm tring to use control in generic handler (ashx) ... not in a page or user control.
A Page is a handler. You want to use a convenience provided by the Page class, but you don't want to inherit from Page. The niceties of Page, such as ClientScript, expect a Page from which to get various information.
You can provide a dummy Page object to your control by setting the Page property of your custom Control:
this.Page = new Page();
...then you will need to set various properties (assuming they are public) which are expected by ClientScriptManager.GetWebResourceUrl():
this.Page.Foo = "bar";
then you can call:
this.Page.ClientScript.GetWebResourceUrl(...);

If this is the specific class that inherits from WebControl page shouldn't be null. If its another class that you are rendering as part of a hierarchy you can add a parameter of type Page and pass the reference of the current page to it.

Ensuring unique ID attribute for elements within ScriptControl

I'm creating a control based on ScriptControl, and I'm overriding the Render method like this:
protected override void Render(HtmlTextWriter writer)
{
RenderBeginTag(writer);
writer.RenderBeginTag(HtmlTextWriterTag.Div);
writer.Write("This is a test.");
writer.RenderEndTag();
RenderEndTag(writer);
}
My question is, what if I want to assign the div an ID attribute and have it be unique on the page, even if there are mulitple instances of my control?
I've seen other people's code that does this:
writer.AddAttribute(HtmlTextWriterAttribute.Id, this.ClientID + "_divTest");
That will prevent naming conflicts between instances of my control, but what if I've already created a div elsewhere on the page that coincidentally has the same ID?
I've also heard about implementing INamingContainer. Would that apply here? How could I use it?
UPDATE:
I've worked around this by overriding CreateChildControls and adding actual controls, as opposed to rendering HTML directly. In that case INamingContainer does its job. However, I'm still curious if there's a way to solve my original problem (unique IDs for directly rendered elements).

INamingController is a marker interface. Implementing it will guarantee you unique ids for each instance of your control.
http://msdn.microsoft.com/en-us/library/system.web.ui.inamingcontainer.aspx
public class MyScriptControl: ScriptControl, INamingContainer {
}

You won't want to create instances of controls just to get unique Ids, there's useless overhead/complexity in that approach. The Control.ID property may not be unique, but the Control.ClientID property will be unique. Therefore
writer.AddAttribute(HtmlTextWriterAttribute.Id, this.ClientID + "_divTest");
that attribute has to be unique unless you use the suffix "_divTest" twice in your custom control.

I am tried to realize your issue:
public class SC : ScriptControl
{
protected override IEnumerable<ScriptDescriptor> GetScriptDescriptors()
{
return null;
}
protected override IEnumerable<ScriptReference> GetScriptReferences()
{
return null;
}
}
//... Page code
protected void Page_PreRender(object sender, EventArgs e)
{
var sc = new SC();
var sc1 = new SC();
Page.Form.Controls.Add(sc);
Page.Form.Controls.Add(sc1);
}
But sc and sc1 have different ClientID. So it is not ASP.NET issue. Look over your realization. May be you generate ids for divs before adding ScriptControls to Page, or may be you try to create 2 divs in the scope of one ScriptControl, or may be you create ScriptConrol2 dynamicly on async-posback and it have the same id as ScriptControl1, that not added dynamicly on postback.